U.S. patent application number 16/106828 was filed with the patent office on 2018-12-13 for organic light emitting display device and method of fabricating the same.
The applicant listed for this patent is LG Display Co., Ltd.. Invention is credited to Jeong-Oh KIM, Yong-Min KIM, Kyoung-Jin NAM.
Application Number | 20180358420 16/106828 |
Document ID | / |
Family ID | 57542849 |
Filed Date | 2018-12-13 |
United States Patent
Application |
20180358420 |
Kind Code |
A1 |
NAM; Kyoung-Jin ; et
al. |
December 13, 2018 |
ORGANIC LIGHT EMITTING DISPLAY DEVICE AND METHOD OF FABRICATING THE
SAME
Abstract
Disclosed are an organic light emitting display device improving
opening ratio and a method of fabricating the same. The organic
light emitting display device includes a light emitting device
disposed at each sub-pixel of a substrate, a pixel circuit driving
the light emitting device, a bank providing a first light emitting
region at a remaining region except for a region where the pixel
circuit is disposed, and a second light emitting region at the
region where the pixel circuit is disposed, and a color filter
disposed at the first and second light emitting regions, wherein at
least one of electrodes included in the pixel circuit includes a
transparent conductive layer at the second light emitting
region.
Inventors: |
NAM; Kyoung-Jin; (Paju-si,
KR) ; KIM; Jeong-Oh; (Goyang-si, KR) ; KIM;
Yong-Min; (Anyang-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG Display Co., Ltd. |
Seoul |
|
KR |
|
|
Family ID: |
57542849 |
Appl. No.: |
16/106828 |
Filed: |
August 21, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15378511 |
Dec 14, 2016 |
10084026 |
|
|
16106828 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 27/322 20130101;
H01L 27/1225 20130101; H01L 27/326 20130101; H01L 51/0023 20130101;
H01L 27/3272 20130101; H01L 27/12 20130101; H01L 27/1255 20130101;
H01L 27/3262 20130101; H01L 29/45 20130101; H01L 27/3276 20130101;
H01L 27/3248 20130101; H01L 2227/323 20130101; H01L 51/56 20130101;
H01L 27/124 20130101; H01L 27/3246 20130101; H01L 27/3258 20130101;
H01L 51/5203 20130101 |
International
Class: |
H01L 27/32 20060101
H01L027/32; H01L 51/56 20060101 H01L051/56; H01L 51/52 20060101
H01L051/52; H01L 51/00 20060101 H01L051/00; H01L 27/12 20060101
H01L027/12 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 29, 2015 |
KR |
10-2015-0188445 |
Claims
1.-10. (canceled)
11. A method of fabricating an organic light emitting display
device having a plurality of sub-pixels comprising: forming a pixel
circuit at each sub-pixel region of a substrate; forming a color
filter on the substrate where the pixel circuit is formed; forming
an anode electrode of a light emitting device connected to the
pixel circuit; forming a bank to define a first emitting light area
where the pixel circuit is not disposed and a second emitting light
area where the pixel circuit is disposed; and forming an organic
light emitting layer and a cathode electrode of the light emitting
device in the first and second light emitting regions, wherein at
least one of electrodes in the pixel circuit includes a transparent
conductive layer and an opaque conductive layer on the transparent
conductive layer, and the opaque conductive layer of the at least
one of electrodes is not provided in the second light emitting
region.
12. The method according to claim 11, wherein: forming the pixel
circuit comprises forming a first source electrode and a first
drain electrode of a switching thin film transistor and a second
source electrode and a second drain electrode of a driving thin
film transistor, on the substrate, forming the first source
electrode, the first drain electrode, the second source electrode
and the second drain electrode comprises: sequentially forming the
transparent conductive layer and an opaque conductive layer on the
substrate; forming a photoresist pattern having a multi-step
structure on the opaque conductive layer; etching the opaque layer
and the transparent layer using the photoresist pattern; ashing the
photoresist pattern; and etching the opaque conductive layer
disposed at the second light emitting region using the ashed
photoresist pattern.
13. The method according to claim 12, wherein: each of the source
electrode and the drain electrode of each of the driving transistor
and the switching transistor is disposed to include the transparent
conductive layer and the opaque conductive layer, which are stacked
at the remaining region except for the second light emitting region
in the pixel circuit, and each of the source electrode and the
drain electrode of each of the driving transistor and the switching
transistor is disposed to include the transparent conductive layer
at the first and second light emitting regions.
14. The method according to claim 12, wherein: each of the source
electrode and the drain electrode of each of the driving transistor
and the switching transistor is disposed to include the transparent
conductive layer and the opaque conductive layer, which are stacked
at a region overlapping the active layer, and each of the source
electrode and the drain electrode of each of the driving transistor
and the switching transistor is disposed to include the transparent
conductive layer at a region non-overlapping the active layer.
Description
[0001] This application claims the benefit of Korean Patent
Application No. 10-2015-0188445, filed on Dec. 29, 2015, which is
hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to an organic light emitting
display device and a method of fabricating the same, and more
particularly, to an organic light emitting display device with
improved opening ratio and a method of fabricating the same.
Discussion of the Related Art
[0003] A display device displaying various information on a screen
is a core technology of the information technology age. Display
devices are developed to become thin, light, portable and
high-performance. To this end, flat display devices, such as
organic light emitting display devices, which control an amount of
light emitted from an organic light emitting layer to display an
image, have been spotlighted, since their weight and volume are
reduced compared to cathode ray tubes (CRTs).
[0004] Organic light emitting diode (OLED) devices are a self-light
emitting device and have various advantages, such as low power
consumption, fast response time, high luminous efficiency, high
luminance and wide viewing angle.
[0005] An organic light emitting display device typically include a
plurality of pixels arranged in a matrix to display an image.
Herein, each pixel includes a light emitting device and a pixel
circuit including a plurality of transistors, which independently
drive the light emitting device. In such an organic light emitting
display device, when the light generated from the organic light
emitting device is emitted to a bottom of a substrate, a plurality
of electrode layers included in the pixel circuit are formed of an
opaque material at a region where the pixel circuit is disposed,
such that the light generated from the organic light emitting
device may not be radiated.
[0006] Accordingly, a conventional organic light emitting display
device has an opening ratio reduced by a region occupied by the
pixel circuit. Furthermore, since a compensating circuit is also
recently provided in each sub-pixel, it may be difficult to secure
high opening ratio.
SUMMARY
[0007] Accordingly, the present invention is directed to a an
organic light emitting display device and a method of manufacturing
the same that substantially obviate one or more problems due to
limitations and disadvantages of the related art.
[0008] An advantage of the present invention is to provide an
organic light emitting display device with improved opening ratio
and a method of fabricating the same.
[0009] Additional advantages, objects, and features of the
invention will be set forth in part in the description which
follows and in part will become apparent to those having ordinary
skill in the art upon examination of the following or may be
learned from practice of the invention. The objectives and other
advantages of the invention may be realized and attained by the
structure particularly pointed out in the written description and
claims hereof as well as the appended drawings.
[0010] To achieve these objects and other advantages and in
accordance with the purpose of the invention, as embodied and
broadly described herein, an organic light emitting display device
having a plurality of sub-pixels may, for example, include a light
emitting device in each sub-pixel of a substrate; a pixel circuit
that drives the light emitting device; a bank that provides a first
light emitting region where the pixel circuit is not disposed and a
second light emitting region where the pixel circuit is disposed;
and a color filter in the first and second light emitting regions,
wherein at least one of electrodes included in the pixel circuit
includes a transparent conductive layer in the second light
emitting region.
[0011] In another aspect, an organic light emitting display device
may, for example, include a bank providing a first light emitting
region at a remaining region except for a region where the pixel
circuit is disposed, and a second light emitting region at the
region where the pixel circuit is disposed. The organic light
emitting display device includes a color filter and a light
emitting device provided at the first and second light emitting
regions. At least one of electrodes included in a pixel circuit
includes a transparent conductive layer at the second light
emitting region, thereby improving opening ratio.
[0012] In yet another aspect, a method of fabricating an organic
light emitting display device having a plurality of sub-pixels may,
for example, include forming a pixel circuit at each sub-pixel
region of a substrate; forming a color filter on the substrate
where the pixel circuit is formed; forming an anode electrode of a
light emitting device connected to the pixel circuit; forming a
bank to define a first emitting light area where the pixel circuit
is not disposed and a second emitting light area where the pixel
circuit is disposed; and forming an organic light emitting layer
and a cathode electrode of the light emitting device in the first
and second light emitting regions, wherein at least one of
electrodes in the pixel circuit includes a transparent conductive
layer in the second light emitting region.
[0013] It is to be understood that both the foregoing general
description and the following detailed description of the present
invention are exemplary and explanatory and are intended to provide
further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this application, illustrate embodiment(s) of
the invention and together with the description serve to explain
the principle of the invention. In the drawings:
[0015] FIG. 1 is a cross-sectional view illustrating an organic
light emitting display device according to an embodiment of the
present invention;
[0016] FIG. 2 is a view illustrating first and second light
emitting regions illustrated in FIG. 1;
[0017] FIGS. 3A to 3J are cross-sectional views illustrating a
method of fabricating the organic light emitting display device
illustrated in FIG. 1; and
[0018] FIGS. 4A to 4D are views illustrating a method of
fabricating first and second source electrodes, first and second
drain electrodes, a data line, and a storage lower electrode
illustrated in FIG. 3D in detail.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0019] Reference will now be made in detail to embodiments of the
invention, examples of which are illustrated in the accompanying
drawings.
[0020] FIG. 1 is a cross-sectional view illustrating an organic
light emitting display device according to an embodiment of the
present invention.
[0021] As illustrated in FIG. 1, each of red, green and blue
sub-pixels of the organic light emitting display device includes a
light emitting device, includes a light emitting device 130, and a
pixel circuit, which independently drives the light emitting device
130. The pixel circuit includes a switching thin film transistor
150, a driving thin film transistor 100, and a storage capacitor
140.
[0022] The switching thin film transistor 150 supplies a data
voltage from a data line DL to a second gate electrode 160 of the
driving thin film transistor 100 based on a scan signal of a scan
line (not shown). The switching thin film transistor 150 includes a
first gate electrode 156 connected to the scan line, a first source
electrode 158 connected to the data line DL, a first drain
electrode 160 connected to a second gate electrode 106, and a first
active layer 154.
[0023] The driving thin film transistor 150 controls a current
supplied from a high voltage line (VDDL in FIG. 2) based on a
driving voltage charged at the storage capacitor 140 to supply the
current proportional to the driving voltage such that the light
emitting device 130 is driven. The driving thin film transistor 100
includes the second gate electrode 106 connected to the first drain
electrode 160, a second source electrode 108 connected to the high
voltage line, a second drain electrode 110 connected to the light
emitting device 130, and a second active layer 104.
[0024] The first and second gate electrodes 156 and 106 of the
switching thin film transistor 150 and the driving thin film
transistor 100 overlap a first oxide semiconductor layer 154 and a
second oxide semiconductor layer 104, respectively, while gate
insulating patterns 112, which are the same patterns as the first
and second gate electrodes 156 and 106, are interposed between the
first and second gate electrodes 153 and 106 and the first and
second active layers 104 and 154. Each of the first and second gate
electrodes 156 and 106 may have a single layer or multilayer form
including at least one selected from the group consisting of
molybdenum (Mo), aluminum (Al), chrome (Cr), gold (Au), titanium
(Ti), nickel (Ni), neodymium (Nd), copper (Cu), or an alloy
thereof, without being limited thereto.
[0025] The first and second active layers 154 and 104 are formed on
the gate insulating patterns 112 to overlap the first and second
gate electrodes 156 and 106, respectively. Thereby, channels are
formed between the first source electrode 158 and the first drain
electrode 160, and between the second source electrode 108 and the
second drain electrode 110. Each of first and second active layers
154 and 104 is formed of a metallic oxide including at least one
selected from the group consisting of Zn, Cd, Ga, In, Sn, Hf, and
Zr, or is formed of polycrystalline silicon or amorphous
silicon.
[0026] The first electrode 158 is connected to the first active
layer 154 via a first source contact hole 164S, which passes
through an interlayer insulating layer 116. The second electrode
108 is connected to the second active layer 105 via a second source
contact hole 124S, which passes through the interlayer insulating
layer 116. The first drain electrode 160 is connected to the first
oxide semiconductor layer 154 via a first drain contact hole 164D,
which passes through the interlayer insulating layer 116. The
second drain electrode 110 is connected to the second oxide
semiconductor layer 104 via a second drain contact hole 124D, which
passes through the interlayer insulating layer 116
[0027] The first drain electrode is electrically connected to the
first electrode 156 of the driving thin film transistor 100 via a
connection electrode (not shown).
[0028] The second drain electrode 110 is connected to a storage
upper electrode 144 exposed by a storage contact hole 146, which
passes through a protective layer 118. The storage upper electrode
144 is connected to an anode electrode 132 exposed by a pixel
contact hole 120, which passes through a planarization layer
128.
[0029] The storage capacitor 140 is disposed at the first light
emitting region EA1. The storage capacitor 140 includes a storage
lower electrode 142 and the storage upper electrode 144, while the
protective layer 118 is interposed between the storage lower
electrode 142 and the storage upper electrode 144. Herein, the
storage lower electrode 142 is electrically connected to the first
drain electrode 160 of the switching thin film transistor 150. The
storage lower electrode 142 is formed of a transparent conductive
material on the interlayer insulating layer 116. The storage upper
electrode 144 is electrically connected to the second drain
electrode 110 of the driving thin film transistor 160. The storage
upper electrode 142 is formed of a transparent conductive material
on the protective layer 118. Thus, the storage lower electrode 142
and the storage upper electrode 144, which constitute the storage
capacitor and are formed of the transparent conductive material,
are disposed at a first light emitting region EA1, such that
decrease of opening ratio due to the storage capacitor 140 may be
prevented.
[0030] The light emitting device 130 includes the anode electrode
132, an organic light emitting layer 134 formed on the anode
electrode 132, and a cathode electrode 136 formed on the organic
light emitting layer 134.
[0031] The anode electrode 132 is connected to the storage upper
electrode 144 exposed by the pixel contact hole 120, which passes
through the planarization layer 148, such that the anode electrode
132 is electrically connected to the second drain electrode 110 via
the storage upper electrode 144. Meanwhile, when a bottom emission
type organic light emitting display device is provided, the anode
electrode 132 is formed of a transparent conductive oxide
(TCO).
[0032] The anode electrode 132 is formed to overlap the switching
thin film transistor 150 and the driving thin film transistor 100
such that the anode electrode 132 is disposed at a second light
emitting region EA2. The anode electrode 132 overlaps the switching
thin film transistor 150 and the driving thin film transistor 100
while the protective layer 118, a color filter 160, and the
planarization layer 128 are interposed between the anode electrode
132, and the switching thin film transistor 150 and the driving
thin film transistor 100. Herein, a distance between each of the
switching thin film transistor 150 and the driving thin film
transistor 100 and the anode electrode 132 corresponds to a
thickness of the color filter 160, thereby preventing increase of
parasitic capacitance.
[0033] The organic light emitting layer 134 is formed on the anode
electrode 132 of the first and second light emitting regions EA1
and EA2, which are exposed by a bank 138. The organic light
emitting layer 134 includes a hole-related layer, the light
emitting layer, and an electron-related layer, which are stacked on
the anode electrode 132 in order or in reverse order.
[0034] As illustrated in FIG. 2, the bank 138 is formed on the
anode electrode 132 to prepare the first and second light emitting
regions EA1 and EA2. The bank 138 exposes the anode electrode 132
disposed at the first and second light emitting regions EA1 and
EA2. In each sub-pixel, the first light emitting region EA1 is
provided at a region, at which the switching thin film transistor
150 and the driving thin film transistor 100 are not formed. In
each sub-pixel, plural second light emitting regions EA2 are
provided at a region, at which the switching thin film transistor
150 and the driving thin film transistor 100 are formed.
[0035] The cathode electrode 136 is formed at an upper surface and
a side surface of the bank 138 in order to face the anode electrode
132 of the first and second light emitting regions EA1 and EA2
while the organic light emitting layer 134 is interposed between
the cathode electrode 136 and the anode electrode 132. When a
bottom emission type organic light emitting display device is
provided, the cathode electrode 136 is formed to have a stacked
structure including a transparent conductive layer, such as an
indium-tin-oxide (ITO) or an indium-zinc-oxide (IZO), and a
metallic layer, such as aluminum (Al), silver (Ag), and Ag:Pb:Cu
(APC).
[0036] The first and second source electrodes 158 and 108, and the
first and second drain electrodes 160 and 110 include transparent
conductive layers 172a and opaque conductive layer 172bs formed on
the transparent conductive layers 172a. Each of the transparent
conductive layers 172a may be formed of a transparent conductive
material such as ITO. Each of the opaque conductive layers 172b may
have a single layer or multilayer form including at least one
selected from the group consisting of molybdenum (Mo), aluminum
(Al), chrome (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium
(Nd), and copper (Cu) or an alloy thereof, without being limited
thereto.
[0037] Particularly, the first and second source electrodes 158 and
108, and the first and second drain electrodes 160 and 110 are
disposed to have a structure, in which the transparent conductive
layer 172a and the opaque conductive layer 172b are stacked, at a
remaining region of the pixel circuit except for the second light
emitting region EA2. In this case, the first and second source
electrodes 158 and 108, and the first and second drain electrodes
160 and 110 are disposed to have a structure, in which the
transparent conductive layer 172a and the opaque conductive layer
172b are stacked, at a region overlapping the first and second
active layers 154 and 104. The opaque conductive layer 172b blocks
light generated from the light emitting device 130, thereby
preventing the first and second active layers 154 and 104 from
becoming conductive due to light from the light emitting device
130. Furthermore, the opaque conductive layer 172b having a high
conductivity may prevent increases of resistive elements of the
first and second source electrodes 158 and 108, and the first and
second drain electrodes 160 and 110.
[0038] The first and second source electrodes 158 and 108, and the
first and second drain electrodes 160 and 110 include the
transparent conductive layer 172a at the first and second light
emitting regions EA1 and EA2. Particularly, the first and second
source electrodes 158 and 108, and the first and second drain
electrodes 160 and 110 include the transparent conductive layer
172a at a non-overlapping area of the first and second active
layers 154 and 104.
[0039] Herein, light passing through the color filter 160 at the
second light emitting region EA2, at which the switching thin film
transistor 150 and the driving thin film transistor 100 are
disposed, is emitted to a bottom of a substrate 101 via the
transparent conductive layers 172a of the first and second source
electrodes 158 and 108, and the first and second drain electrodes
160 and 110. Accordingly, light is emitted from the second light
emitting region EA2 as well as the first light emitting region EA1,
such that opening ratio may be improved and thus, it may be easy to
realize a high-resolution.
[0040] Furthermore, the electrodes corresponding to the contact
holes disposed at the pixel circuit include the transparent
conductive layers 172a. For example, the storage upper electrode
144 and the second drain electrode 110 overlapping the storage
contact hole 146 includes the transparent conductive layer 172a,
such that light is emitted from an area corresponding to the
storage contact hole 146, thereby increasing opening ratio.
Besides, the electrodes disposed at regions corresponding to the
contact holes provided for connecting the first drain electrode 160
to the second gate electrode 106 include the transparent conductive
layers 172a.
[0041] Table 1 illustrates opening ratio of an example, in which
light is emitted at the first and second light emitting regions EA1
and EA2, and a comparative example, in which light is emitted at
the first light emitting region EA1. It shows that the red and
green sub-pixels of the example improve opening ratio of over 17%
in comparison with the red and green sub-pixels of the comparative
example. It shows that the blue sub-pixel of the example improves
opening ratio of over 21% in comparison with the blue sub-pixel of
the comparative example.
TABLE-US-00001 TABLE 11 Opening Red Green Blue ratio sub-pixel
sub-pixel sub-pixel Comparative 22.43% 22.43% 29.52% example
(4357.08 .mu.m.sup.2) (4357.08 .mu.m.sup.2) (5809.44 .mu.m.sup.2)
Example 25.94% 25.81% 35.56% (5106.26 .mu.m.sup.2) (5080.83
.mu.m.sup.2) (7001.86 .mu.m.sup.2)
[0042] FIGS. 3A to 3J are cross-sectional views illustrating a
method of fabricating the organic light emitting display device
illustrated in FIG. 1.
[0043] Referring to FIG. 3A, the first and second active layers 154
and 104 are formed on the substrate 101.
[0044] In detail, after a semiconductor material is deposited on
the substrate 101, the semiconductor material is etched by a
photolithography process and an etching process to form the first
and second active layers 154 and 104.
[0045] Referring to FIG. 3B, the first and second gate electrodes
156 and 106 and the gate insulating patterns 112, which have
identical patterns, are formed on the substrate 101 where the first
and second active layers 154 and 104 are formed.
[0046] In detail, a gate insulating layer is formed on the
substrate 101 where the first and second active layers 154 and 104
are formed. A gate metallic layer is formed on the gate insulating
layer using a deposition method such as a sputtering process. The
gate insulating layer is formed of an inorganic insulating material
such as SiOx and SiNx. The gate metallic layer is formed of a
single layer or multilayer form including Mo, Ti, Cu, AlNd, Al, Cr
or an alloy thereof. Then, the gate metallic layer and the gate
insulating layer are simultaneously patterned by a photolithography
process and an etching process to form the first and second gate
electrodes 156 and 106 and the gate insulating patterns 112, which
have identical patterns.
[0047] Referring to FIG. 3C, the interlayer insulating layer 116
having the first and second source contact holes 164S and 124S and
the first and second drain contact holes 164D and 124D is formed on
the substrate 101 where the first and second gate electrodes 156
and 106 are formed.
[0048] In detail, the interlayer insulating layer 116 is formed on
the substrate 101, where the first and second gate electrodes 156
and 106 are formed, by a deposition method such as a
plasma-enhanced chemical vapor deposition (PECVD). Then, the
interlayer insulating layer 116 is patterned by a photolithography
process and an etching process to form the first and second source
contact holes 164S and 124S and the first and second drain contact
holes 164D and 124D.
[0049] Referring to FIG. 3D, the first and second source electrodes
158 and 108, the first and second drain electrodes 160 and 110, and
the storage lower electrode 142 are formed on the interlayer
insulating layer 116 having the first and second source contact
holes 164S and 124S and the first and second drain contact holes
164D and 124D. Hereinafter, forming the first and second source
electrodes 158 and 108, the first and second drain electrodes 160
and 110, and the storage lower electrode 142 will be described in
detail with reference to FIGS. 4A to 4D.
[0050] As illustrated in FIG. 4A, the transparent conductive layer
172a and the opaque conductive layer 172b are sequentially stacked
on the interlayer insulating layer 116 having the first and second
source contact holes 164S and 124S and the first and second drain
contact holes 164D and 124D by a deposition method such as a
sputtering process. Then, after a photoresist material is coated on
the opaque conductive layer 172b, the photoresist material is
exposed and developed using a halftone mask to form a photoresist
pattern 174 having a multi-step structure. The photoresist pattern
174 having the multi-step structure includes a first photoresist
pattern 174a having a first thickness and a second photoresist
pattern 174b having a second thickness which is greater than the
first thickness. The transparent conductive layer 172a and the
opaque conductive layer 172b are etched using the photoresist
pattern 174 having the multi-step structure as a mask to form the
data line DL, the first and second source electrodes 158 and 108,
the first and second drain electrodes 160 and 110, and the storage
lower electrode 142, respectively, as illustrated in FIG. 4B.
Herein, the transparent conductive layer 172a and the opaque
conductive layer 172b of each of the data line DL, the first and
second source electrodes 158 and 108, the first and second drain
electrodes 160 and 110, and the storage lower electrode 142 are
formed to have identical patterns. Subsequently, as illustrated in
FIG. 4C, the photoresist pattern 174 having the multi-step
structure is ashed and the first photoresist pattern 174a is
removed and the thickness of second photoresist pattern 174b is
lowered. Then, the opaque conductive layer 172b exposed by the
second photoresist pattern 174b is etched using the second
photoresist pattern 174b having the lowered thickness due to the
ashing process as a mask. Accordingly, the first and second source
electrodes 158 and 108 and the first and second drain electrodes
160 and 110 include the transparent conductive layers 172a at the
second light emitting region EA2 of the pixel circuit. The first
and second source electrodes 158 and 108 and the first and second
drain electrodes 160 and 110 include the transparent conductive
layers 172a and the opaque conductive layers 172b at remaining
areas except for the second light emitting region EA2 of the pixel
circuit. The storage lower electrode 142 includes the transparent
conductive layer 172a at the first light emitting region EA1.
[0051] Referring to FIG. 3E, the protective layer 118 having the
storage contact hole 146 is formed on the interlayer insulating
layer 116 where the first and second source electrodes 158 and 108,
the first and second drain electrodes 160 and 110, and the storage
lower electrode 142 are formed.
[0052] In detail, the protective layer 118 is formed on the
interlayer insulating layer 116 where the first and second source
electrodes 158 and 108, the first and second drain electrodes 160
and 110, and the storage lower electrode 142 are formed. The
protective layer 118 is formed of an inorganic insulating layer
such as SiOx and SiNx. Then, the protective layer 118 is patterned
by a photolithography process and an etching process to form the
storage contact hole 146.
[0053] Referring to FIG. 3F, the storage upper electrode 144 is
formed on the protective layer 118 having the storage contact hole
146.
[0054] In detail, a transparent conductive layer is deposited on
the protective layer 118 having the storage contact hole 146.
Subsequently, the transparent conductive layer is patterned by a
photolithography process and an etching process to form the storage
upper electrode 144.
[0055] Referring to FIG. 3G, the color filter 160 is formed on the
substrate 101 where the storage upper electrode 144 is formed.
[0056] In detail, after a color resin is deposited on the substrate
101 where the storage upper electrode 144 is formed, the color
resin is patterned by a photolithography process to form the color
filter 160.
[0057] Referring to FIG. 3H, the planarization layer 128 having the
pixel contact hole 120 is formed on the substrate 101 where the
color filter 160 is formed.
[0058] In detail, an organic layer such as an acrylic resin is
entirely deposited on the substrate 101 where the color filter 160
is formed, to form the planarization layer 128. Then, the
planarization layer 128 is patterned by a photolithography process
to form the pixel contact hole 120.
[0059] Referring to FIG. 3I, the anode electrode 132 is formed on
the planarization layer 128 having the pixel contact hole 120.
[0060] In detail, a transparent conductive layer is deposited on
the planarization layer 128 having the pixel contact hole 120.
Then, the transparent conductive layer is patterned by a
photolithography process and an etching process to form the anode
electrode 132.
[0061] Referring to FIG. 3J, the bank 138, the organic light
emitting layer 134, and the cathode electrode are sequentially
formed on the substrate 101 where the anode electrode 132 is
formed.
[0062] In detail, a photoresist layer for the bank 138 is entirely
deposited on the substrate 101 where the anode electrode 132 is
formed. Subsequently, the photoresist layer for the bank 138 is
patterned by a photolithography process to form the bank 138. Then,
the organic light emitting layer 134 with white light emission is
entirely deposited on the substrate 101 where the bank 138 is
formed. The cathode electrode 136 is formed on the substrate 101
where the organic light emitting layer 134 is formed.
[0063] According to an embodiment of the present invention, light
is emitted from the second light emitting region EA2 where the
pixel circuit is disposed as well as the first light emitting
region EA1 where the pixel circuit is not disposed such that
opening ratio may be improved and thus, it may be easy to realize a
high-resolution.
[0064] Meanwhile, an embodiment of the present invention discloses
that light having the same color is emitted from the first and
second areas EA1 and EA2 by way of example. However, light having
different colors can also be emitted from the first and second
areas EA1 and EA2.
[0065] Furthermore, an embodiment of the present invention
discloses that areas of the second light emitting regions EA2 are
the same at the red, green, and blue sub-pixels. However, the areas
of the second light emitting regions EA2 may be different at the
red, green, and blue sub-pixels in consideration of durability of
the red, green, and blue sub-pixels. Namely, the area of the second
light emitting region EA2 of the blue sub-pixel which has lower
durability than the red and green sub-pixels may be greater than
the areas of the second light emitting regions EA2 of the red and
green sub-pixels.
[0066] As described above, according to an embodiment of the
present invention, light is emitted at the second light emitting
region where the pixel circuit is disposed as well as the first
light emitting region where the pixel circuit is not disposed, such
that opening ratio may be improved and thus, it may be easy to
realize a high-resolution.
[0067] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention
without departing from the spirit or scope of the inventions. Thus,
it is intended that the present invention covers the modifications
and variations of this invention provided they come within the
scope of the appended claims and their equivalents.
* * * * *